[webkit-reviews] review requested: [Bug 84306] [Qt][WK2] Fixed layers are shaking when zoom level is not 1.0 due to a rounding error. : [Attachment 139036] Patch.

[bugzilla-daemon at webkit.org]

Yael <yael.aharon at nokia.com> has asked	for review:
Bug 84306: [Qt][WK2] Fixed layers are shaking when zoom level is not 1.0 due to
a rounding error.
https://bugs.webkit.org/show_bug.cgi?id=84306

Attachment 139036: Patch.
https://bugs.webkit.org/attachment.cgi?id=139036&action=review

------- Additional Comments from Yael <yael.aharon at nokia.com>
When zooming, we need to be careful about how to convert the visible rect from
float to int. Using toAlignedRect can produce inconsistent width and height
when we are scrolling. This patch carefully modifies each piece of the visible
rect, to avoid such rounding errors. In addition, the TransformMatrix we use
for painting, needs to be adjusted for the same rounding error.